1. Technical Field
The present invention relates to a circuit device, an electronic device, and the like.
2. Related Art
Heretofore, circuit devices that perform various processing using signals from a resonant circuit are known. For example, JP-A-2011-155836 discloses techniques relating to controlling supply of power in the power receiving apparatus that charges a battery using a contactless power transmission system, one technique of which involves performing information communication between the power receiving side (power receiving apparatus) and the power transmitting side using signals from the resonant circuit.
Also, a typical ASK (Amplitude Shift Keying) modulation method is disclosed in FIGS. 4(a) to (c) of JP-A-7-143188. Transmission data that is to undergo ASK modulation is shown in FIG. 4(a), a carrier wave, which is the output waveform of the resonant circuit, is shown in FIG. 4(b), and the transmission waveform of the ASK modulated signal is shown in FIG. 4(c).
In the above technology, ASK modulation is realized by switching the carrier wave on and off based on the transmission data, as shown in FIGS. 4(a) to (c) of JP-A-7-143188.
However, with the above technology, since the carrier wave is generated by continuously operating the oscillation circuit (resonant circuit), as shown in FIG. 4(b), the power consumption of the oscillation circuit cannot be reduced, and this stands as an impediment to reducing power consumption.